Karl-Heinz Mahrt, Christoph Waldmann; Field proven high speed micro optical density profiler sampling 1000 times per second with 10-6 precision, Proceedings of MTS/IEEE OCEANS'88 Conference, pp. 497 - 504, October 1988.
K.-H. Mahrt, H. C. Waldmann, W. Kroebel; A newly developed in situ-measuring oceanographical probe sensing the optical index of refraction of sea water with new aspects of salinity and density determinations, Proceedings of MTS/IEEE OCEANS'82 Conference, pp. 266 - 271, September 1982.